Early Labor?

I am 32 weeks pregnant and since about 30 weeks I have been having pain/pressure down there. I had my appointment with my OB today and she didn’t seem to think it was normal and told me if the pain gets worse or is persistent to head to labor and delivery to be checked out to make sure I’m not in premature labor or dilating. It only happens when I’m up and moving around especially walking. I thought maybe it was lightening crotch but she never mentioned that. Has anyone else experienced this? I don’t know at what point I should go to L&D because it is consistent when I’m walking but when I’m sitting down or laying down I don’t really feel anything. I was really hoping she would have went ahead and checked to make sure no dilation has happened just to be safe. This is my first baby so all of these feelings are so unfamiliar to me.